Dilophosaurus was a speedy, slender, bipedal (walked on two legs), meat-eater that lived during the early Jurassic period. It was a theropod (a meat-eating dinosaur) about 20 feet (6 m) long, about 5 feet (1.5 m) tall at the hip, and weighing about 650 to 1,000 pounds (300 kg to 450 kg). It had two thin, bony, almost semi-circular crests on its head; these may have been for mating displays. It had short arms with three-fingered hands and strong legs with four-toed feet (one toe was a dewclaw ). Both fingers and toes had claws. It had hollow bones and an S-shaped, curved neck. Dilophosaurus lived about 201 to 189 million years ago, during the early Jurassic period.¬†Dilophosaurus may have roved in packs, since three specimens were found together in Arizona, USA. Dilophosaurus was a carnivore, a meat eater. It had loosely attached jaws which would have made killing animals with its teeth difficult. It must have killed with its clawed arms and legs, and/or scavenged carcasses. Dilophosaurus walked on two muscular legs and was a relatively fast runner, leaving bird-like footprints on land. Some of its fossilized footprints are only impressions of the claw-tips. This indicates that Dilophosaurus may have been walking in water at the time. Dilophosaurus’ leg length was about 1.65 m; it’s stride length (distance between footprints) was about 2.13 m.